JL battery charging start stop not working

JimLee

Hooked
JL's have a high parasitic draw from the factory, even Jeep knows this as they recommend disconnecting if you are going to leave your Jeep sitting for three weeks or more.

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Do with that knowledge what you will.
 

AZ_JLUR

Member
I have heard of a method to disable the Aux battery and the ESS system (both of which I hate) by doing the following:

1. Disconnect the Aux battery ground cable from the main battery ground terminal/cable cluster and tape the Aux ground cable off and secure it in a safe place.
2. Remove fuse F42 from the PDC to disable the ESS system.

I've replaced both batteries twice on my 2020 out of an "abundance of caution". I don't like to hike in the heat.

Anyone have any strong feelings one way or the other on this method?

TIA
 
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onlyone

Active Member
I have heard of a method to disable the Aux battery and the ESS system (both of which I hate) by doing the following:

1. Disconnect the Aux battery ground cable from the main battery ground terminal/cable cluster and tape the Aux ground cable off and secure it in a safe place.
2. Remove fuse F42 from the PDC to disable the ESS system.

I've replaced both batteries twice on my 2020 out of an "abundance of caution". I don't like to hike in the heat.

Anyone have any strong feelings one way or the other on this method?

TIA
I did the same without the fuse pull because I use the tazer to disable the start stop.
 

AZ_JLUR

Member
Thanks @onlyone

Pulling fuses makes me nervous, but for me (totally stock) I'm thinking the Tazer to make one setting change is overkill.

The "Auto Start Eliminator" or similar that @JimLee mentions might be a better choice for me.


So, the "Auto Start Eliminator" and disconnecting the Aux battery would work? Any cautions?

Or, just the "Auto Start Eliminator" and leave the Aux battery connected?

TIA
 
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JimLee

Hooked
Thanks @onlyone

Pulling fuses makes me nervous, but for me (totally stock) I'm thinking the Tazer to make one setting change is overkill.

The "Auto Start Eliminator" or similar that @JimLee mentions might be a better choice for me.


So, the "Auto Start Eliminator" and disconnecting the Aux battery would work? Any cautions?

Or, just the "Auto Start Eliminator" and leave the Aux battery connected?

TIA
I'm not 100% sure about whether you need to pull the fuse or disconnect anything as I went to a dual batt system pretty early on that completely rerouted the aux batt wiring to the mains, I currently have ESS disabled through Tazer also just to keep the computer happy and not get warnings (it'll also still stop the engine at stops if not disabled the way I'm wired up). I've got an auto stop/start eliminator laying around somewhere from before I got Tazer if anyone wants it. Personally, if I was still stock on the electrical system I'd find a way to get rid of the aux batt completely, along with disabling ESS, because of the way it's been know to trash the main batt when it goes bad, and why carry it if you aren't using it. I've read somewhere that there's a jumper you can put in to bypass the aux batt but I'm not clear on the details because I haven't needed any other solutions than the ones I already have.
 

onlyone

Active Member
Thanks @onlyone

Pulling fuses makes me nervous, but for me (totally stock) I'm thinking the Tazer to make one setting change is overkill.

The "Auto Start Eliminator" or similar that @JimLee mentions might be a better choice for me.


So, the "Auto Start Eliminator" and disconnecting the Aux battery would work? Any cautions?

Or, just the "Auto Start Eliminator" and leave the Aux battery connected?

TIA
Pretty sure you don’t need to pull the fuse, but I’m not sure what year they changed a few things. For giggles, I tried my start/stop and it still works normal with just the Main battery. Just pull the neg wire on the Aux, tape it up and set it next to the battery.
 
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B Nelson

Member
I hope this is a proper thread for posting about the aux battery delete.
My wife and I are 2nd owners of a 2021 JLUR w/3.6 and auto trans. I've been watching videos and reading about the aux battery delete, which I want to do. I just went out to the Jeep and noticed the F42 fuse has already been removed and there's only one negative cable going to the main battery and I couldn't find the aux battery cable in the general area (Maybe the prior owner removed it completely). Anyway, my wife tells me the ESS still works. Am I missing something?
 

B Nelson

Member
I just read a post, which stated the ESS will function properly w/o the aux battery hooked up, however it'll be using the main battery for starting, instead of the aux battery. My bad for posting before a thorough research. Just glad to be rid of the aux battery. Take care
 
I just read a post, which stated the ESS will function properly w/o the aux battery hooked up, however it'll be using the main battery for starting, instead of the aux battery. My bad for posting before a thorough research. Just glad to be rid of the aux battery. Take care
Do you have the 3.6 with etorque? If so, the battery is underneath along the driveshaft, not under the main one. You could also grab a tazer and it will keep the system turned off when you disable it using the button on the dash.
 

RoadNomad

New member
I thought I would share the following as there are so many different versions of the ESS and battery disable.

I recently purchased an 18 Rubi JLU that the autostop/start was not working properly and also giving a dash error.

The dealer I purchased from ended up replacing both batteries that resolved the problem. I lived with the feature manually switch it off from time to time. The interesting thing is if the Jeep sat for a few weeks without being used I would get an error on the dash, a Yellow A in a circle with an escalation mark I was told by the dealer that this happens from time to time if the small secondary battery is not up to a full charge and that driving the Jeep more often would prevent it from re-occuring. Anytime it did happen all I had to do is shut of and restart and poof it was gone.

My wife said she didn't like the fact she had to push buttons to deactivate the stop/start every time she started the vehicle and that feature has got to go.

After some research I looked into purchasing a Tazer but the lack of actual telephone support in ability of the company to answer email questions and the cost turned me off to the product, I kept searching for an alternative.

I found www.smartstopstart.com they were able to answer all my questions, have an excellent track record and no negative mark. On top of that they have a money back warranty. Another plus was easy installation that does not affect the vehicles security nor does it need to be un-married or removed when the vehicle goes in for service.

To install unplug one cable from the Jeep SWG and insert the module in between the cable removed and the SWG. You can choose to use the Start/Stop feature or not it remembers the last setting.

So onto the last part of the puzzle, that little pain in the ass battery that causes more problems then it's worth. Now, if your small battery is good and you want to leave it in place under the fuse box and do the following:

1. Remove the F42 ESS fuse from the fusebox, this fuse controls the relay that controls the connection of the 2 batteries, removing this fuse will disable the charge status of the little battery and prevent errors from occuring on the dash displays.

2. Next remove the Aux (little battery) negative battery cable, tape it off and secure it so the loose end won't cause any problems. At this point your done, you have isolated the aux battery and prevented it from ever discharging or ruining your main battery when it fails. You have also disable the system for accessing it or checking its charge status.

Your auto stop/start system will work as it did from the factory if you choose to enable it by pressing its button. With the www.smartstopstart.com
interface in place it will remember the last condition of the button, if you switched off the feature auto stop/start will work like normal, if you turned it off it will stay off until you press the button again. A great solution that wont break the bank or leave your stranded.

Personally I think its a dumb system that does little for fuel economy but becomes a maintenance nightmare with extra costs for batteries, service visits, starters and more only to save a few gallons over say thousands of miles.
 
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